JP2000240470A - Gas turbine device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas turbine device to facilitate the execution of a turbine washing work without the occurrence of any risk. SOLUTION: This gas turbine device comprises a mixture fluid producer 5 to produce mixture fluid of a particular substance and high pressure air; and a plurality of injection nozzles 9 arranged in an annular shape in a spot situated upper stream from a turbine blade. Mixture fluid produced by the mixture fluid producer is injected through the nozzles and a turbine blade surface is washed through impact collision of the mixture fluid against the turbine blade. In a so formed gas turbine device, the mixture fluid producer 5 and a plurality of injection nozzles 9 are intercoupled through a piping, and mixture fluid switching means 20-28 to feed mixture fluid from the mixture fluid producer alternately to a plurality of the injection nozzles are arranged in the middle of the piping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a gas turbine device, and more particularly to a gas turbine device provided with a cleaning device for cleaning a blade surface of a turbine.

[0002]

2. Description of the Related Art Gas turbines conventionally used for power generation or motive power are characterized in that the type of fuel used is relatively strictly limited. That is, after starting combustion, a low-quality fuel that easily generates dust such as soot may be used. If the operation is continued using such low-quality fuel, dust generated by the combustion adheres to the turbine blades, and the turbine efficiency gradually decreases.

[0003] Therefore, it is necessary to occasionally clean the turbine blades in order to restore turbine efficiency. Various methods can be considered for cleaning the turbine blades, and each method is adopted. In general, a cleaning material (hard particles) is charged from the upstream side of the turbine during the operation of the gas turbine, and the gas flow in the turbine is increased. So-called dry cleaning, which removes dust adhering to the blade surface by using the impact of particles on the blade colliding with the turbine blade, is employed.

As the cleaning material for the dry cleaning, a material having an appropriate hardness is selected, and a material called a crushed nut shell of a hard plant seed shell is used. In general, a method of supplying a cleaning material to a turbine is such that an injection nozzle is attached in advance near a combustor located on the upstream side of the turbine, and the cleaning material is supplied through a pipe and the nozzle. .

The cleaning material is supplied to the injection nozzle as a mixed fluid with compressed air having a pressure higher than the pressure in the combustor. In order to effectively clean the turbine vane on the most upstream side to which the most dust adheres, the injection nozzle is mounted at a position where the cleaning material injected from the injection nozzle can directly collide with the turbine vane. Since the turbine vanes are radially fixed to the turbine casing and form a ring, a plurality of injection nozzles are also arranged so as to equally divide the ring.

As described above, a plurality of injection nozzles are provided for one gas turbine. However, from the economical point of view, it is common practice to provide only one generator for the mixed fluid of the cleaning material and the compressed air. A pipe is connected between the mixed fluid generator and the injection nozzle. Inside the pipe, a projection that causes the cleaning material, which is a solid particle, to be caught and adhered, causing blockage of the flow path. There must be no objects or obstacles.

Further, it is necessary that the cross-sectional area of the flow path does not largely change on the way, that is, the pipe path must not cause a large pressure loss. That is, although the pressure, flow rate, and amount of cleaning material mixed with the compressed air supplied from the mixed fluid generator are adjusted and supplied,
If a large pressure loss occurs in the flow path, the specified flow rate,
This is because the density, flow rate, pressure, and the like are lost, and the intended cleaning effect cannot be obtained. For this reason, it is desirable to connect a single pipe between the mixed fluid generator and the injection nozzle.

This commonly used piping has a uniform flow path cross-sectional area, is flexible, and has a connector which can be easily attached and detached. Then, at the time of cleaning, this flexible pipe is connected to an arbitrary injection nozzle to clean the turbine stationary blade sector. After cleaning the turbine vane sector, the flexible pipe is connected to another injection nozzle for cleaning. In this manner, the cleaning is sequentially performed for each sector. A valve is attached to the connection port of each injection nozzle so as to prevent the internal combustion gas from flowing backward and being ejected while the pipe is not connected.

Japanese Patent Application Laid-Open No. Sho 57-157 relates to a gas turbine device having this type of cleaning device.
Japanese Patent Application Laid-Open No. 186021, Japanese Patent Application Laid-Open No. 7-164321, and Japanese Patent Application Laid-Open No. 9-170452.

[0010]

As described above, the cleaning of the turbine blades in the gas turbine device is performed during the operation of the turbine. That is, the combustion is performed in a state where the combustor and the gas turbine main body are at a high temperature, and the injection nozzle attached to the combustor is also at a high temperature. Further, since the inside of the turbine is at a high pressure, the pipe connection port of the injection nozzle is temporarily opened when the pipe is attached or detached, and the combustion gas inside may flow backward from the injection nozzle and be ejected. This reconnection of pipes involves the danger of touching high-temperature parts, and there is the danger that high-temperature gas inside will blow out into the atmosphere due to work mistakes.
I hated that this was a lot of time and nerves.

Further, in order to operate the gas turbine economically, it is necessary to immediately clean the turbine when the turbine efficiency is reduced. However, conventionally, there is a danger during operation as described above. Cleaning cannot be performed frequently, and as a result, the gas turbine has been operated with reduced efficiency for a longer period of time, and the gas turbine has a tendency to adversely affect the economy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gas turbine apparatus of this kind in which a turbine cleaning operation can be easily performed without danger. It is in.

[0013]

That is, the present invention provides a mixed fluid generator for generating a mixed fluid of particulate matter and high-pressure air, and a plurality of injection nozzles arranged in an annular shape on the upstream side of the turbine blade. Wherein the mixed fluid generated by the mixed fluid generator is ejected from the nozzle, and the surface of the turbine blade is cleaned by collision impact of the mixed fluid on the turbine blade. A mixed fluid that connects a generator and the plurality of injection nozzles with a pipe or a branched pipe, and supplies a mixed fluid from the mixed fluid generator to the plurality of injection nozzles alternately in the middle of the pipe. No switching means is provided to achieve the intended purpose.

In this case, a three-way valve is provided at a branch portion of the branch pipe, and the three-way valve is used to branch the pipe and switch the supply of the mixed fluid. Further, the pipe and the mixed fluid switching means have the same internal flow path cross-sectional area. Further, the mixed fluid switching means is formed by a ball valve.

That is, in the gas turbine device formed as described above, the mixed fluid generator and the plurality of injection nozzles are connected by a pipe, and the mixed fluid from the mixed fluid generator is supplied in the middle of the pipe. Since the mixed fluid switching means for alternately supplying the plurality of injection nozzles is provided, only by operating the mixed fluid switching means, the flow rate, the density, the flow rate, and the pressure at which the mixed fluid can be efficiently turbine-cleaned are respectively set. It is possible to transfer the nozzle to any of the plurality of injection nozzles while maintaining the same, and the turbine cleaning operation can be easily performed without danger.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows the gas turbine device and the cleaning device in a diagram. In the figure, 42 is a turbine, 40 is an air compressor, 41 is a combustor, 421
Is a turbine stationary blade, 5 is a mixed fluid generator, 1 is a cleaning material tank, and 9 is an injection nozzle.

The gas turbine is composed of an air compressor 40, a combustor 41, and a turbine 42, and its operation is performed as follows. That is, the air sucked into the air compressor 40 becomes high-pressure air at the outlet of the air compressor 40 and enters the combustor 41. The compressed air is mixed with fuel in the combustor 41 and ignited by an ignition device to generate high-pressure combustion gas. The high pressure combustion gas drives the turbine 42.

The turbine includes several tens of turbine vanes 421 radially fixed to a turbine casing and several tens of turbine blades 422 radially fixed to a rotating shaft.
And one stage, and several stages of combinations of stationary blades and moving blades. The combustion gas generated in the combustor 41 expands when passing between the turbine vanes 421, and converts thermal energy into kinetic energy. The turbine blade 422 receives the kinetic energy of the combustion gas and converts it into a force for rotating the rotating shaft, that is, mechanical energy. The ratio at which the thermal energy of the combustion gas can be converted into kinetic energy is one of the factors that determine the efficiency of the gas turbine.

The efficiency of a gas turbine is evaluated by the ratio of the fuel consumed by the combustor to the mechanical energy obtained by the turbine 42. When dust adheres to the blade surface of the turbine 42 and disturbs the flow of the combustion gas passing therethrough, the rate at which the thermal energy of the combustion gas is converted into kinetic energy decreases, and the machine obtained by the turbine 42 Energy decreases. Gas turbine dry cleaning is used as a means for recovering this decrease in turbine efficiency.

The gas turbine dry cleaning apparatus comprises a tank 1,
It comprises a tank outlet valve 2, a hopper 3, a hopper outlet valve 4, a mixed fluid generator 5, a compressed air stop valve 6, a pressure gauge 7, an atmosphere release valve 8, direction switching valves 20 to 28, and a stop valve 29. The turbine vanes 421 arranged radially are divided into ten sectors S0 to S9, and the injection nozzle 9 is positioned in each of the sectors so that the cleaning material sprayed from the injection nozzle directly hits the turbine vanes 421. Attached to.

The process of the turbine dry cleaning will be described below. (Step 1) The operations from (described later) to (Step 8) are defined as one cleaning cycle, and a total of 10 cleaning cycles are performed.
The cycle is repeated, and the cleaning of one turbine is completed. However, in (Step 5), the operation of the switching valves 20 to 28 and the operation of the stop valve 29 are different, since the sector to which the cleaning material is transported is changed with the progress of the cycle.
FIG. 2 shows an operation chart of the switching valves 20 to 28 and the stop valve 29 as the cycle proceeds.

(Step 1) The tank 1 stores an amount of cleaning material necessary for cleaning one turbine. The direction switching valves 20 to 28 are located at positions where the flow path is directed to the downstream switching valve. All other valves are closed. The compressed air is
It is supplied to the inlet of the compressed air stop valve 6. FIG. 1 shows this state.

(Step 2) The air release valve 8 is opened to make the pressure in the cleaning device after the hopper 3 equal to the atmospheric pressure.

(Step 3) The tank outlet valve 2 is opened, and the cleaning material is moved to the hopper 3 by free fall. After a certain period of time, the tank outlet valve 2 is closed.

(Step 4) When the air release valve 8 is closed and the compressed air stop valve 6 is opened, the compressed air is supplied to the hopper 3 and the mixed fluid generator 5, and the internal pressure of the hopper 3 and the mixed fluid generator 5 is reduced. Become equal.

(Step 5) When the pipeline is switched according to the chart of FIG. 2 to form a route to a predetermined sector,
Only compressed air flows through the mixed fluid generator 5 to a given sector.

(Step 6) When the hopper outlet valve 4 is opened,
When the cleaning material falls freely from the hopper 3, the mixed fluid generator 5
Into a mixed fluid mixed with the compressed air and transported to a predetermined sector through a pipe.

(Step 7) The mixed fluid conveyed to the predetermined sector is jetted from the jet nozzle toward the turbine vanes within the range of the sector to remove dust adhering to the blade surface.

(Step 8) The hopper outlet valve 4 is closed, the direction switching valves 20 to 28 and the stop valve 29 are returned to the same state as in (Step 1), and the washing operation in this sector is completed.

FIGS. 3 and 4 show the direction switching valves 20 to 28 and the stop valve 29 used as the branch switching mechanism in this embodiment.
Is shown. This is commonly known as a ball valve and is already used in a wide range of industrial fields. The direction switching valves 20 to 28 are three-way switching ball valves. A spherical valve element 52 that rotates around a central axis is housed in the valve box 51. The valve body 52 has a through hole, and a path from the inlet to the outlet A or the outlet B can be selected by rotating the valve body.

The stop valve 29 is a two-way switching type ball valve. A spherical valve element 54 that rotates around a central axis is housed in the valve box 53. The valve body 54 also has a penetrated hole, and when the valve body is rotated, the path from the inlet to the outlet can be opened and closed. The through holes formed in any of the valve bodies are almost the same as the inner diameter of the pipe connected to the valve, and there is almost no pressure loss of the fluid before and after passing through the valve. Also, since there are no protrusions, obstacles, etc. in the fluid path inside the valve, the solid cleaning material is caught,
Will stick and eventually will not cause blockage of the pathway.

The effect of the turbine dry cleaning depends on properties such as the flow rate, density, and flow rate of the cleaning material injected from the injection nozzle. They are adjusted artificially by the pressure and flow rate of the compressed air supplied to the turbine cleaning device. When transferring the cleaning material from one mixed fluid generator to one injection nozzle, there is no unexpected pressure loss in the middle of the transport path, so make sure to transport the mixed fluid of the expected properties. As a result, the cleaning material could be sprayed from all the spray nozzles as expected.

If a connection is made to a plurality of injection nozzles at the same time and they are connected by a branch pipe, an inadvertent pressure loss occurs at the branch portion. In this case, the pressure is reduced, and the jetting cannot be performed as expected, and the cleaning effect is reduced. vice versa,
If the supply pressure is increased in anticipation of the pressure loss, an excessive flow rate of the cleaning material will be injected in a certain sector, and the turbine blades will be worn.

While having a pipe connected to a plurality of injection nozzles from one mixed fluid generator at the same time, using a switching mechanism utilizing a ball valve at a branch portion, one pipe connected to one selected injection nozzle When the transfer is carried out while forming the piping path of the above, an inadvertent pressure loss does not occur, so that effective cleaning of the turbine blades in any sector can be guaranteed.

As described above, in the gas turbine apparatus formed as described above, since the mixed fluid generator and each injection nozzle are connected by the branch pipe having the direction switching mechanism, the turbine cleaning can be efficiently performed. It is possible to transport the mixed fluid to any of the multiple spray nozzles without mounting and removing it while maintaining the flow rate, density, flow rate, and pressure that can be generated, which is dangerous for nozzle switching work Can be implemented without any gender,
It is possible to avoid danger to the person during work. In addition, the efficiency of gas turbine operation can be improved because turbine cleaning can be performed frequently.

[0036]

As described above, according to the present invention, it is possible to obtain a gas turbine apparatus of this kind that can perform a turbine cleaning operation without danger.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing one embodiment of a gas turbine device of the present invention.

FIG. 2 is a diagram showing a state of a switching valve when switching a piping path of a cleaning device in the gas turbine device of the present invention.

FIG. 3 is a structural diagram of branch switching means used in an embodiment of the present invention.

FIG. 4 is a structural diagram of branch switching means used in an embodiment of the present invention.

[Explanation of symbols]

1 ... cleaning material tank, 2 ... tank outlet valve, 3 ... hopper, 4
... hopper outlet valve, 5 ... mixed fluid generator, 6 ... compressed air stop valve, 7 ... pressure gauge, 8 ... atmosphere release valve, 9 ... injection nozzle,
20 to 28: switching valve, 29: stop valve, 40: compressor,
41: Combustor, 42: Turbine, 421: Turbine vane, 422: Turbine rotor blade, S0 to S9: Sector equally dividing the ring formed by the turbine vane, 51: Valve box, 52: Valve element,
53: valve box, 54: valve body.

Claims (5)

[Claims] 1. A mixed fluid generator for generating a mixed fluid of particulate matter and high-pressure air, and a plurality of injection nozzles arranged in an annular shape on an upstream side of a turbine blade. In a gas turbine device configured to inject the generated mixed fluid from the nozzle and perform cleaning of the turbine blade surface by collision impact of the mixed fluid on the turbine blade, the mixed fluid generator and the plurality of injection nozzles And a mixed fluid switching means for alternately supplying a mixed fluid from the mixed fluid generator to the plurality of injection nozzles in the middle of the pipe. Turbine equipment. 2. A mixed fluid generator for generating a mixed fluid of particulate matter and high-pressure air, and a plurality of injection nozzles arranged in an annular shape on an upstream side of a turbine blade, wherein the mixed fluid generator includes: In a gas turbine device configured to inject the generated mixed fluid from the nozzle and perform cleaning of the turbine blade surface by collision impact of the mixed fluid on the turbine blade, the mixed fluid generator and the plurality of injection nozzles And a mixed fluid switching means for alternately supplying the mixed fluid from the mixed fluid generator to the plurality of injection nozzles in the middle of the branch pipe. Gas turbine equipment. 3. A three-way valve is provided at a branch part of the branch pipe,
3. The gas turbine apparatus according to claim 2, wherein the three-way valve switches the branch of the pipe and the supply of the mixed fluid. 4. The gas turbine apparatus according to claim 2, wherein the branch pipe and the mixed fluid switching means have the same internal flow path cross-sectional area. 5. The gas turbine device according to claim 1, wherein said mixed fluid switching means is formed by a ball valve.